Abiraterone acetate (ZYTIGA) is transferred to abiraterone in vivo, which is an oral cytochrome P450 (CYP450) oxidase c17 inhibitor and inhibits synthesis of androgen by inhibiting CYP450 c17 enzyme which is a key enzyme to hormone synthesis in testis and other part of a body. On Apr. 28, 2011, US Food and Drug Administration (FDA) approved the use of abiraterone acetate (Zytiga) in combination with prednisone (steroids) in the treatment of advanced (metastatic) prostate cancer which has been treated with docetaxel (chemotherapy) and is refractory to exairesis. The chemical formula of abiraterone acetate is shown as:

WO9320097A firstly reported this compound and its synthesis method, wherein dehydroepiandrosterone acetate as a starting material reacts with triflic anhydride to obtain dehydroepiandrosterone acetate trifluoromethanesulfonate, which then reacts with diethyl-(3-pyridyl) borane through Suzuki coupling to obtain the compound. The synthesis route is shown as follows:

References, such as WO9509178, Org. Prep. Proced. Int, 1997, 29(1), 123-134, etc., reported another synthesis scheme for this compound:

All of the above schemes require purification by column chromatography, and are not suitable for industrial manufacturing.
In WO2006021776 and WO2006021777, the same synthetic route as that in WO9320097 was used, however, in the post-processing, the crude abiraterone acetate was purified by salifying and crystallization with methanesulfonic acid, thereby removing most of the impurities including dehydroepiandrosterone acetate. But the disadvantages of this process are that upon salification of the crude abiraterone acetate, the time of filtration is pretty long, the resulting cake is viscous, impurities are prone to remain, and there are many impurities and the content of each impurity is more than 1%.
In CN102030798, the crude abiraterone acetate is purified by salifying and crystallization with trifluoromethanesulfonic acid. The difficulties in filtration is solved and the content of impurity is lower that that in WO2006021776 and WO2006021777, however, the final product is still oily, which can not meet the pharmaceutical standard by recrystallization.
In summary, the available methods for purifying abiraterone acetate have the following disadvantages: yield and purity are low; there are multiple impurities, the contents of which are high; the final product is oily; and purification through column chromatography is necessary to obtain a product meeting pharmaceutical standards; the cost is high, and it is not suitable for large-scale manufacturing.